July 7 (Reuters) - South Korean electric vehicle (EV) battery producer SK On has declared itself in crisis as its customers struggle with disappointing EV sales in Europe and the U.S., the Financial Times reported on Sunday.

Chief Executive Lee Seok-hee announced a series of cost-cutting and working-practice measures on Monday, describing them as a state of "emergency management", the report said, citing a letter to employees. (Reporting by Akanksha Khushi in Bengaluru; Editing by William Mallard)